Malicious PDF — malware analysis report

Static analysis result for SHA-256 de8498fb32a7194a…

MALICIOUS

PDF

70.3 KB Created: 2021-10-07 12:19:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: ab829c1d6ffdd34003a50761f535c96e SHA-1: 909c998ee6f10b8b0ae1a3d29337dabd3892917a SHA-256: de8498fb32a7194a43b1591308d7ab8a015d511b2a39ad660e7ccfb861863f0a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple potentially compromised or disposable hosting sites. The embedded URLs, including one pointing to a WordPress upload directory, reinforce this behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://simoncaulkin.com/images/mikosanesimu.pdf In PDF document text
    • http://autosoftware.company/autoresponders_images/files/10028773196.pdfIn PDF document text
    • http://caphegiabao.com/upload/fck/file/62847315003.pdfIn PDF document text
    • http://cosmosimpex.com/app/webroot/ckfinder/userfiles/files/kalovigifejudofetowu.pdfIn PDF document text
    • http://djarkitek.com/temp/vinney/HTML/userfiles/file/sufura.pdfIn PDF document text
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/214e6adacd544419c83192fead70a7d9/zodozafipezepu.pdfIn PDF document text
    • http://nedvizhimost-v-sharm-el-sheikhe.ru/uploads/files/migufojulisuki.pdfIn PDF document text
    • http://heaig.org/editor/ckfinder/userfiles/files/51423951262.pdfIn PDF document text
    • http://1-cities.com/blog_images/blog_/file/pilodatopakiwu.pdfIn PDF document text
    • http://autoset66.ru/admin/ckfinder/userfiles/files/vemalafa.pdfIn PDF document text
    • http://regimhotelierbucuresti.com/images/userfiles/4003288194.pdfIn PDF document text
    • https://www.projectorrentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140e181c9787---kalixunerinu.pdfIn PDF document text
    • https://www.poole.ed.jp/system/ckfinder/userfiles/files/nixagonebixisajavipa.pdfIn PDF document text
    • http://comitatoamiantovelodromo.org/userfiles/file/rofodesugorumunegujuxodu.pdfIn PDF document text
    • http://golden-candies.ru/webroot/files/files/23538426014.pdfIn PDF document text
    • http://dalieuht.com/app/webroot/uploads/files/suvozot.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/3bd82b57b90dc1384c2edc6d8a51f637/nizokijeza.pdfIn PDF document text
    • http://isagenixmakessense.com/ckfinder/userfiles/files/vuvizarurabafukawelev.pdfIn PDF document text
    • http://grawerlik.pl/userfiles/file/49747203837.pdfIn PDF document text
    • https://nexapos.com/upload/files/40711356259.pdfIn PDF document text
    • https://polaria.cz/images/file/zutupofuzawasurebiloku.pdfIn PDF document text
    • http://german-ex.com/images/blog/file/juzegexexiji.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=powerful+four+letter+wordsPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b350.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB350 10176 bytes
SHA-256: c9801c6c954f4ba85e2728dc90fd3b20586b54bba0bce6b2d12b02b466013b62
font_01_sfnt_off0000ca5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA5C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e26e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE26E 16460 bytes
SHA-256: fa064571e6b472af3307d81136383611648ae490857798a9372d54baf0362033